Unity Development Grid Placement for a Prototype

PLEASE do not just message without reading THIS,

This has the FULL DETAILS OF WHAT WE WANT TO DO THANK YOU.

Game Editor Prototype

Function: Grid Placement
Objective: Allows user to place objects (building, unit, landscape) snapping to the grid accordingly.

The Script should have these properties:
-Grid Size (int x, int y) : Size of the grid should be equivalent to the map size.
-Cell Size (float) : Cell size should be static and private, accessible to us only.
-Grid Status (bool) : Check if cell is occupied, for pathfinding usage etc.
-Grid Object (Class) : If occupied, what is within the grid.

The Grid Class and the grid control script should also have functions/methods as follow:
-Instantiating the Grid (and setup)
-Add/Modify/Remove item from/to the grid cells.
-Auto Grid Snapping
-TBD


Function: Action Logging
Objective: Users will have their action logged into a list within a panel. The list will be used for undo/redo function for the editor.

The Class should be public so that it can be access from other script for logging purpose.

Logging should happen every time users complete an action.

The Script should have these properties:
-List<> or Dictionary<> : To store the logs and its data.
-Log Object <T> : Type of action done, store this object to List<>.
-Previous State <T> : If new data is given, store previous data in this variable.
-Current State <T> : Current data of the Object (e.g.: object position)

What should be logged:
-Object Placement/Removal (and its position in the grid before and after)
-Add/Modify/Remove object script ()
-TBD

What shouldn’t be logged:
-Pressing button
-Select/Deselect object(s)
-TBD